> My issues all stem from that it works, but does the wrong thing

It's an opportunity, not a problem. Because it means there's a gap in your specifications and then your tests.

I use Aider not Claude but I run it with Anthropic models. And what I found is that comprehensively writing up the documentation for a feature spec style before starting eliminates a huge amount of what you're referring to. It serves a triple purpose (a) you get the documentation, (b) you guide the AI and (c) it's surprising how often this helps to refine the feature itself. Sometimes I invoke the AI to help me write the spec as well, asking it to prompt for areas where clarification is needed etc.